The Chemistry of CRL 618

The synthesis of benzene in the protoplanetary nebula CRL 618 Paul

The slowly expanding envelope of CRL 618 probed with HC 3 N rotational ladders

Lines from HC 3 N and isotopic substituted species in ground and vibrationally excited states produce crowded millimeter and submillimeter wave spectra in the C-rich protoplanetary nebula CRL618. The complete sequence of HC 3 N rotational lines from J=9–8 to J=30–29 has been observed with the IRAM 30m telescope toward this object. Lines from a total of 15 different vibrational states (including...

A Survey of Large Molecules toward the Proto–planetary Nebula Crl 618

We present the results of our survey toward the proto–planetary nebula CRL 618 for several large, highly saturated, oxygen-bearing organic molecules of biological importance including acetaldehyde (CH3CHO), acetic acid (CH3COOH), dimethyl ether (CH3OCH3), ethanol (CH3CH2OH), formic acid (HCOOH) and methyl formate (HCOOCH3); large carbon chain molecules including methyl cyanide (CH3CN), methylcy...

Physical conditions in the Protoplanetary Nebula CRL 618 derived from observations of vibrationally excited HC 3

We used the Effelsberg 100 m and IRAM 30 m telescopes to observe vibra-tionally excited cyanoacetylene (HC 3 N) in several rotational transitions toward the proto-planetary nebula CRL 618. Lines from 9 different vibrationally excited states with energies ranging up to 1600 K above ground were detected. The lines show P Cygni profiles indicating that the HC 3 N emission originates from an expand...

0 Fe b 20 09 Collimated Fast Wind in the Pre - Planetary Nebula CRL 618

Collimated fast winds (CFWs) have been proposed to operate during the post-AGB evolutionary phase (and even earlier during the late AGB phase), responsible for the shaping of pre-planetary nebulae (PPNs) and young planetary nebulae (PNs). This paper is a follow-up to our previous study of CFW models for the well-studied PPN CRL 618. Previously, we compared our CFW models with optical observatio...